The known devices with liquid reservoir typically comprise a tray having a bottom wall and side walls, defining at least one reservoir designed to contain a liquid, and a platform, designed to be placed on the tray and to support a growing substrate, the platform comprising a substantially flat main portion provided with at least one well the bottom of which comprises at least one orifice capable of communicating with the liquid contained in the tray.
Document FR 2 851 419 describes a first example of a device of this type, provided, in particular, with ribs delimiting the breakage zones. Document FR 2 884 107 proposes a second example of such a device, which also comprises means for carrying liquid in the reservoir, arranged at least partially on the platform and separate from the orifice of the well, making it possible to limit even further the amount of liquid used for growing the surface in question.
In practice, the surface to be cultivated is covered with these devices placed side by side, and then a layer of appropriate material, such as sand, is placed on the platforms. The latter operation is carried out by small machines which move by rolling on the water-reservoir devices while pouring out the sand. Then, bigger earth-moving machines, that can weigh up to 3 or 4 tons, level the layer of sand thus deposited to obtain the desired configuration of the land.
The earth-moving machines running on the layer of sand does not cause damage to the water-holding devices, that latter being well covered by the sand. However, the sand-pouring operation carried out by the small machines may cause the devices to break.
Specifically, for matters of installation time, in particular when it involves equipping large areas, such as a stadium for example, the small machines have to run on the water-reserve devices even when they pour out the sand. The layer of sand may therefore be thin, or even non-existent, when these machines pass, which may lead to the devices breaking.